CORE B: PROJECT SUMMARY The mission of the Mass Spectrometry Core is to make advanced proteomics experiments available to all three project investigators. This Program Core will utilize equipment and expertise that are part of an existing Lerner Research Institute facility that provides mass spectrometry based proteomic expertise. This includes several mass spectrometric instruments that are necessary for advanced proteomic experiments, highly experienced personnel who can help plan and carry out these experiments, and the software tools needed to analyze the proteomic data. The Core activities will be overseen by Dr. Stark and by Dr. Belinda Willard, the Director of the Institute facility. A research technologist funded by and dedicated to the Program Core will assist all three project leaders with sample preparation and analysis with assistance and data analysis provided by Institute facility personnel. All three program project investigators and co-investigators have utilized the Institute proteomics core extensively in previous years, including Drs. Stark, Sen, Hamilton, Li, and Jackson. The inclusion of the mass spectrometry core in this Program will allow all investigators to perform large-scale quantitative proteomic experiments and will serve as an important resource integrating the scientific themes of the overall Program.